light estimateLast updated 2026-08-20

Best text-to-speech API for IVR and phone agents

Default pickDeepgram Aura-2

For IVR menus and phone agents — where latency and cost per minute dominate — Deepgram Aura-2 is the strongest default: it is aimed squarely at voice-agent and IVR workloads, with streaming, a large English voice catalog, low measured latency (about 293 ms time-to-first-audio) and the cheapest clean per-character rate at $30 per million characters. Cartesia Sonic is the alternative when every millisecond counts, at about 271 ms measured. A light estimate from public benchmarks and pricing, August 2026.

DefaultDeepgram Aura-2goedkoopsteDeepgram Aura-2snelsteCartesia Sonic 3 / Sonic 3.5

Provider offerings

Provider offerings compared on Price, ELO, TTFA, Langs and capabilities
Offering	Price ($/1M chars)	ELO	TTFA	Langs	Capabilities
ElevenLabs Multilingual v2 / Eleven v3ElevenLabs	100	1179	653 ms	29	streamingcloning
Cartesia Sonic 3 / Sonic 3.5Cartesia	39*	1203	271 ms	42	streamingcloning
Google Gemini 3.1 Flash TTSGoogle	12*	1212	—	—	streaming
OpenAI gpt-4o-mini-ttsOpenAI	15*	—	775 ms	50	streaming
MiniMax Speech 2.5 TurboMiniMax	78	—	—	—	streamingcloning
Deepgram Aura-2Deepgram	30	—	293 ms	7	streaming
SpeechifyAI Simba 3.2Speechify	10*	1240	398 ms	30	streamingcloning

* token-/credit-priced — the headline understates real per-unit cost, so it is excluded from the cheapest ranking.

Sources